To build your application for Chrome OS, follow the instructions for Building Apps for Android.
In addition to the Android build instructions, you need to configure some Chrome OS Build Settings.
To make your application support all Chrome OS devices:
Go to File > Build Settings. The Build Settings window opens.
In the Platform section, select Android.
Click Player Settings. The Project Settings window opens with the Player option selected.
In the Settings for Android section, expand Other Settings.
In the Target Architectures section, enable both the ARMv7 and ARM64 properties as well the x86 and x86–64 properties.
Build to create your build.
Build And Run to create your app and run your build on the platform you have selected.
Note: To run a built APK on your Chrome OS device, you must connect with adb.